Multiple Sounding Reference Signal Transmissions Triggered by Downlink Control Information

The present application for patent is a continuation of U.S. patent application Ser. No. 17/575,341 by ABDELGHAFFAR et al., entitled “MULTIPLE SOUNDING REFERENCE SIGNAL TRANSMISSIONS TRIGGERED BY DOWNLINK CONTROL INFORMATION,” filed Jan. 13, 2022, which claims priority to and the benefit of U.S. Provisional Patent Application No. 63/138,512 by ABDELGHAFFAR et al., entitled “MULTIPLE SOUNDING REFERENCE SIGNAL TRANSMISSIONS TRIGGERED BY DOWNLINK CONTROL INFORMATION,” filed Jan. 17, 2021, each of which is assigned to the assignee hereof, and each of which is expressly incorporated by reference herein.

The following relates to wireless communications, including multiple sounding reference signal transmissions triggered by downlink control information.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long-Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as a user equipment (UE). In some wireless communications systems, the UEs may be configured to transmit sounding reference signal (SRS) resource sets to a base station to allow the base station to determine channel quality and efficiently schedule communications with the UE. Efficient techniques for triggering a UE to transmit multiple SRS resource sets may be desirable.

The described techniques relate to improved methods, systems, devices, and apparatuses that support multiple sounding reference signal (SRS) transmissions triggered by downlink control information (DCI). A user equipment (UE) may use the techniques described herein to identify slots in which to transmit multiple SRS resource sets triggered by one or more DCI messages. In one aspect, the UE may determine a next available slot for transmitting an SRS resource set based on the available information at a timestamp and on a reference slot (e.g., the slot in which the latest DCI message is received or a slot that is offset from the slot in which the latest DCI message is received). In yet another aspect, the UE may receive one or more indications of slots in which to transmit the multiple SRS resource sets. In yet another aspect, the UE may follow one or more rules to identify slots in which to transmit the multiple SRS resource sets.

A method for wireless communication at a UE is described. The method may include receiving first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receiving second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, identifying a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identifying a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set, where the first available slot is offset from the reference slot by a first offset (e.g., a first available slot offset) indicated in the first downlink control information and the second available slot is offset from the reference slot by a second offset (e.g., a second available offset) indicated in the second downlink control information, and transmitting the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receive second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, identify a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identify a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set, where the first available slot is offset from the reference slot by a first available slot offset indicated in the first downlink control information and the second available slot is offset from the reference slot by a second available slot offset indicated in the second downlink control information, and transmit the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, means for receiving second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, means for identifying a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, means for identifying a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set, where the first available slot is offset from the reference slot by a first available slot offset indicated in the first downlink control information and the second available slot is offset from the reference slot by a second available slot offset indicated in the second downlink control information, and means for transmitting the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receive second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, identify a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identify a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set, where the first available slot is offset from the reference slot by a first available slot offset indicated in the first downlink control information and the second available slot is offset from the reference slot by a second available slot offset indicated in the second downlink control information, and transmit the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot for the first sounding reference signal resource set may include operations, features, means, or instructions for identifying the first available slot for the first sounding reference signal resource set from one or more candidate slots following a processing time after a timestamp determined based on receiving the first downlink control information and the second downlink control information. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the timestamp as a last symbol of a control channel that includes the second downlink control information or a last symbol of a search space associated with the control channel that includes the second downlink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot for the first sounding reference signal resource set may include operations, features, means, or instructions for identifying the first available slot for the first sounding reference signal resource set from one or more candidate slots following a timestamp determined based on receiving the first downlink control information and the second downlink control information. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the timestamp as a symbol preceding one or more symbols in a candidate slot available for the first sounding reference signal resource set by a processing time.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second downlink control information may be received and correctly decoded by the timestamp. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least one of the first downlink control information or the second downlink control information may be received and correctly decoded by the timestamp.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the reference slot to be a slot in which the second downlink control information may be received. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication of an offset in the second downlink control information and determining the reference slot based on the offset and a slot in which the second downlink control information may be received.

A method for wireless communication at a UE is described. The method may include receiving a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, receiving downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and transmitting the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, receive downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and transmit the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, means for receiving downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and means for transmitting the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, receive downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and transmit the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, in the downlink control information, a bit field indicating the first available slot offset and the second available slot offset. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, in the configuration message, a first list of triggering codes for triggering transmission of the first sounding reference signal resource set, where each triggering code in the first list corresponds to an offset for the first sounding reference signal resource set and receiving, in the downlink control information, a triggering code from the first list of triggering codes triggering transmission of the first sounding reference signal resource set and indicating the first available slot offset.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, in the downlink control information, a first bit field indicating the first available slot offset and a second bit field indicating the second available slot offset. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the first bit field indicates the first available slot offset and the second bit field indicates the second available slot offset based on an order of the first bit field and the second bit field in the downlink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the first available slot for the first sounding reference signal resource set before the second available slot for the second sounding reference signal resource set and identifying the second available slot for the second sounding reference signal resource set based on the first available slot being unavailable for the second sounding reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on the first available slot offset being greater than the second available slot offset. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on the first available slot offset being less than the second available slot offset.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on a first index of the first sounding reference signal resource set and a second index of the second sounding reference signal resource set. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on a first usage of the first sounding reference signal resource set and a second usage of the second sounding reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on the first sounding reference signal resource set being scheduled for transmission on partial frequency resources. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on a first configuration of the first sounding reference signal resource set and a second configuration of the second sounding reference signal resource set, where the first configuration and the second configuration each include a number of sounding reference signal resources, a transmit power, a frequency hopping configuration, a number of repetitions, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot before the second available slot may include operations, features, means, or instructions for identifying the first available slot before the second available slot based on the first available slot offset being different than the second available slot offset, a first index of the first sounding reference signal resource set, a second index of the second sounding reference signal resource set, the first sounding reference signal resource set being scheduled for transmission on partial frequency resources, a first configuration of the first sounding reference signal resource set, a second configuration of the second sounding reference signal resource set, or any combination thereof, where the first configuration and the second configuration each include a number of sounding reference signal resources, a transmit power, a frequency hopping configuration, a number of repetitions, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first available slot indicated for the first sounding reference signal resource set and the second available slot indicated for the second sounding reference signal resource set may be a same slot. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the first sounding reference signal resource set, the second sounding reference signal resource set, or both may include operations, features, means, or instructions for transmitting the first sounding reference signal resource set on a first subset of symbols in the same slot and transmitting the second sounding reference signal resource set on a second subset of symbols in the same slot.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the first sounding reference signal resource set, the second sounding reference signal resource set, or both may include operations, features, means, or instructions for transmitting either the first sounding reference signal resource set or the second sounding reference signal resource set. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining whether to transmit the first sounding reference signal resource set or the second sounding reference signal resource set based on a first usage, index, or configuration of the first sounding reference signal resource set and a second usage, index, or configuration of the second sounding reference signal resource set.

A method for wireless communication at a base station is described. The method may include transmitting a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, transmitting downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and receiving the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, transmit downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and receive the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, means for transmitting downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and means for receiving the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit a configuration message indicating a first list of offsets for a first sounding reference signal resource set and a second list of offsets for a second sounding reference signal resource set, transmit downlink control information triggering transmission of the first sounding reference signal resource set and the second sounding reference signal resource set and indicating a first available slot offset from the first list of offsets corresponding to a first available slot for the first sounding reference signal resource set and a second available slot offset from the second list of offsets corresponding to a second available slot for the second sounding reference signal resource set, and receive the first sounding reference signal resource set in the first available slot, the second sounding reference signal resource set in the second available slot, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, in the downlink control information, a bit field indicating the first available slot offset and the second available slot offset. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, in the configuration message, a first list of triggering codes for triggering transmission of the first sounding reference signal resource set, where each triggering code in the first list corresponds to an offset for the first sounding reference signal resource set and transmitting, in the downlink control information, a triggering code from the first list of triggering codes triggering transmission of the first sounding reference signal resource set and indicating the first available slot offset.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, in the downlink control information, a first bit field indicating the first available slot offset and a second bit field indicating the second available slot offset. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the first bit field indicating the first available slot offset and the second bit field indicating the second available slot offset may include operations, features, means, or instructions for transmitting the first bit field and the second bit field in an order such that the first bit field corresponds to the first sounding reference signal resource set and the second bit field corresponds to the second sounding reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first available slot indicated for the first sounding reference signal resource set and the second available slot indicated for the second sounding reference signal resource set may be a same slot. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first sounding reference signal resource set, the second sounding reference signal resource set, or both may include operations, features, means, or instructions for receiving the first sounding reference signal resource set on a first subset of symbols in the same slot and receiving the second sounding reference signal resource set on a second subset of symbols in the same slot. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first sounding reference signal resource set, the second sounding reference signal resource set, or both may include operations, features, means, or instructions for receiving either the first sounding reference signal resource set or the second sounding reference signal resource set.

A method for wireless communication at a user equipment (UE) is described. The method may include receiving, at a first time, a first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receiving, at a second time, second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, where the first time occurs before the second time, identifying a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identifying a timestamp as a last symbol of a control channel that includes the second downlink control information or a last symbol of a search space associated with the control channel that includes the second downlink control information, identifying each of a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set based at least in part on a processing time after the timestamp, where the first available slot is offset from the reference slot by a first available slot offset and the second available slot is offset from the reference slot by a second available slot offset, and transmitting the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, at a first time, first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receive, at a second time, second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, where the first time occurs before the second time, identify a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identify a timestamp as a last symbol of a control channel that includes the second downlink control information or a last symbol of a search space associated with the control channel that includes the second downlink control information, identify each of a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set based at least in part on a processing time after the timestamp, where the first available slot is offset from the reference slot by a first available slot offset and the second available slot is offset from the reference slot by a second available slot offset, and transmit the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, at a first time, a first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, means for receiving, at a second time, second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, where the first time occurs before the second time, means for identifying a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, means for identifying a timestamp as a last symbol of a control channel that includes the second downlink control information or a last symbol of a search space associated with the control channel that includes the second downlink control information, means for identifying a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set based at least in part on a processing time, where the first available slot is offset from the reference slot by a first available slot offset and the second available slot is offset from the reference slot by a second available slot offset, and means for transmitting the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, at a first time, first downlink control information from a first transmission and reception point, the first downlink control information triggering transmission of a first sounding reference signal resource set, receive, at a second time, second downlink control information from a second transmission and reception point, the second downlink control information triggering transmission of a second sounding reference signal resource set, where the first time occurs before the second time, identify a reference slot for the first sounding reference signal resource set and the second sounding reference signal resource set, identify a timestamp as a last symbol of a control channel that includes the second downlink control information or a last symbol of a search space associated with the control channel that includes the second downlink control information, identify each of a first available slot for the first sounding reference signal resource set and a second available slot for the second sounding reference signal resource set based at least in part on a processing time after the timestamp, where the first available slot is offset from the reference slot by a first available slot offset and the second available slot is offset from the reference slot by a second available slot offset, and transmit the first sounding reference signal resource set in the first available slot and the second sounding reference signal resource set in the second available slot.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the first available slot for the first sounding reference signal resource set may include operations, features, means, or instructions for identifying the first available slot for the first sounding reference signal resource set from one or more candidate slots, where the timestamp may be determined based on receiving the first downlink control information and the second downlink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the reference slot to be a slot in which the second downlink control information may be received.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication of an offset in the second downlink control information and determining the reference slot based on the offset and a slot in which the second downlink control information may be received.

In some wireless communications systems, user equipment (UEs) may be configured to transmit sounding reference signal (SRS) resource sets to a base station. A UE may support periodic and aperiodic transmissions of SRS resource sets. To facilitate aperiodic transmissions of SRS resource sets, the base station may transmit downlink control information (DCI) to the UE to trigger transmissions of the SRS resource sets. In some cases, to improve reliability, a base station may transmit multiple DCI messages to the UE via at least one transmission and reception point (TRP), and each DCI message may trigger the UE to transmit at least one SRS resource set. In some other cases, the base station may transmit a single DCI message triggering the UE to transmit multiple SRS resource sets. In any case, it may be challenging for the UE to identify appropriate resources for transmitting the multiple SRS resource sets (e.g., to utilize resources efficiently and prevent conflicts).

As described herein, a wireless communications system may support efficient techniques at a UE for transmitting multiple SRS resource sets. In particular, the UE may use the techniques described herein to identify slots in which to transmit multiple SRS resource sets triggered by one or more DCI messages. In one aspect, the UE may determine a next available slot for transmitting an SRS resource set based on the available information at a timestamp and on a reference slot (e.g., the slot in which the latest DCI message is received or a slot that is offset from the slot in which the latest DCI message is received). In yet another aspect, the UE may receive one or more indications of slots in which to transmit the multiple SRS resource sets. In yet another aspect, the UE may follow one or more rules to identify slots in which to transmit the multiple SRS resource sets. In yet another aspect, the UE may support conflict resolution techniques to identify slots in which to transmit the multiple SRS resource sets when the UE is triggered to transmit multiple SRS resource sets in a same slot.

Aspects of the disclosure introduced above are described below in the context of a wireless communications system. Examples of processes and signaling exchanges that support multiple SRS transmissions triggered by DCI are then described. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to multiple SRS transmissions triggered by DCI.

illustrates an example of a wireless communications systemthat supports multiple sounding reference signal transmissions triggered by downlink control information in accordance with aspects of the present disclosure. The wireless communications systemmay include one or more base stations, one or more UEs, and a core network. In some examples, the wireless communications systemmay be a Long-Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications systemmay support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stationsmay be dispersed throughout a geographic area to form the wireless communications systemand may be devices in different forms or having different capabilities. The base stationsand the UEsmay wirelessly communicate via one or more communication links. Each base stationmay provide a coverage areaover which the UEsand the base stationmay establish one or more communication links. The coverage areamay be an example of a geographic area over which a base stationand a UEmay support the communication of signals according to one or more radio access technologies.

The UEsmay be dispersed throughout a coverage areaof the wireless communications system, and each UEmay be stationary, or mobile, or both at different times. The UEsmay be devices in different forms or having different capabilities. Some example UEsare illustrated in. The UEsdescribed herein may be able to communicate with various types of devices, such as other UEs, the base stations, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in.

The base stationsmay communicate with the core network, or with one another, or both. For example, the base stationsmay interface with the core networkthrough one or more backhaul links(e.g., via an S1, N2, N3, or other interface). The base stationsmay communicate with one another over the backhaul links(e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations), or indirectly (e.g., via core network), or both. In some examples, the backhaul linksmay be or include one or more wireless links.

One or more of the base stationsdescribed herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

A UEmay include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UEmay also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UEmay include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEsdescribed herein may be able to communicate with various types of devices, such as other UEsthat may sometimes act as relays as well as the base stationsand the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in.